Dual cap assembly having multiple passages

Abstract

A dual cap assembly having multiple passages, may include a pipe device having a plurality of separate passages; a first cap device detachably mounted at a position where the passages diverge in the pipe device to close a first passage; and a second cap device detachably mounted on the first cap device to close a second passage, wherein when the first cap device is separated from the pipe device, the first passage is opened, and when the second cap device is separated with the first cap device mounted on the pipe device, the second passage is opened while the first passage is closed.

What is claimed is: 
     
       1. A dual cap assembly having a plurality of passages, the cap assembly comprising:
 a pipe device having a plurality of separate passages; 
 a first cap device detachably mounted at a position where the passages diverge in the pipe device to close a first passage; and 
 a second cap device detachably mounted on the first cap device to close a second passage, 
 wherein, when the first cap device is separated from the pipe device, the first passage is configured to be opened, and when the second cap device is separated with the first cap device mounted on the pipe device, the second passage is configured to be opened while the first passage is closed. 
 
     
     
       2. The cap assembly of  claim 1 , wherein the pipe device has a fuel injection passage for keeping fuel and a urea injection passage for keeping urea, and
 the cap assembly further includes a guide pipe disposed at an inlet of the fuel injection passage and connected to the urea injection passage, separating the fuel injection passage and the urea injection passage. 
 
     
     
       3. The cap assembly of  claim 2 , wherein the guide pipe has a fixing portion surrounding the inlet of the fuel injection passage, and a circumferential portion, which has an open side and is wider than the fixing portion, forms a channel with the fixing portion and is connected to the urea injection passage. 
     
     
       4. The cap assembly of  claim 3 , wherein within a guide portion, the circumferential portion extends to a greater height than the fixing portion. 
     
     
       5. The cap assembly of  claim 3 , wherein a block diaphragm is disposed on the circumferential portion and elastically turns toward the fixing portion to contact the fixing portion. 
     
     
       6. The cap assembly of  claim 5 , wherein a plurality of block diaphragms is disposed and separated from each other around an internal side of the circumferential portion, and the block diaphragms each have a first end portion rotatably disposed on the circumferential portion and a second end portion connected to a spring to be elastically supported inwardly. 
     
     
       7. The cap assembly of  claim 6 , wherein the block diaphragms are disposed such that first and second edge portions of adjacent block diaphragms overlap each other. 
     
     
       8. The cap assembly of  claim 1 , wherein the first cap device has a lower cap which is detachably mounted on the guide pipe and closes the fuel injection passage in contact with the inlet of the fuel injection passage when mounted on the guide pipe, and an upper cap that closes an open side of the guide pipe and has a mounting hole for mounting the second cap device. 
     
     
       9. The cap assembly of  claim 8 , wherein a coupling portion which is inserted into the inlet of the fuel injection passage is formed at the lower cap, and corresponding threads are formed on an external side of the coupling portion and an internal side of the inlet of the fuel injection passage. 
     
     
       10. The cap assembly of  claim 8 , wherein a thread is formed along a circumference of the mounting hole of the upper cap and the second cap device has a coupling portion which is thread-fastened to the mounting hole, and a grip is protrudingly formed and is formed across a center of the coupling portion. 
     
     
       11. The cap assembly of  claim 10 , wherein protrusive handles are formed on the upper cap at positions aligned straight with the grip of the second cap device, and
 when the second cap device is thread-fastened to the mounting hole, the grip and the handles are disposed in a straight line, and when the second cap device is turned by 90° or more, the second cap device is unfastened. 
 
     
     
       12. The cap assembly of  claim 8 , wherein the lower cap is thread-fastened to the fuel injection passage and has first fixing steps protruding at predetermined intervals on a top portion thereof and having a slope, and
 the upper cap is disposed on the lower cap and has first locking steps having a slope corresponding to the slope of the first fixing steps. 
 
     
     
       13. The cap assembly of  claim 12 , wherein first fixing extensions are elastically bent up and down and are formed at predetermined intervals on the lower cap, and the first fixing steps are formed at end portions of the first fixing extensions. 
     
     
       14. The cap assembly of  claim 12 , wherein the second cap device further includes:
 an internal cap which is thread-fastened to the mounting hole of the upper cap and has second fixing steps protruding at predetermined intervals on a top portion thereof and having a slope; and 
 an external cap which is disposed over the internal cap and has a slope corresponding to the slope of the second fixing steps. 
 
     
     
       15. The cap assembly of  claim 14 , wherein threads for thread-fastening the lower cap of the first cap device and the fuel injection passage and threads for thread-fastening the internal cap of the second cap device and the upper cap are formed in opposite directions thereof. 
     
     
       16. The cap assembly of  claim 14 , wherein the slopes of the first fixing steps and the slopes of the second fixing steps are inclined in opposite directions, and the slopes of the first locking steps and the slopes of the second locking steps are formed in opposite directions thereof. 
     
     
       17. The cap assembly of  claim 14 , wherein inclination angles of the first fixing steps and the first locking steps are greater than inclination angles of the second fixing steps and the second locking steps. 
     
     
       18. The cap assembly of  claim 8 , wherein protrusive handles are formed around the mounting hole of the upper cap, and the handles have a fixing mechanism that slides in and out of and is inserted into a fixing groove formed at the guide pipe when the first cap device is fastened to the guide pipe so that the first cap device is maintained in the closed state. 
     
     
       19. The cap assembly of  claim 18 , wherein the fixing mechanism has a button elastically supported by a spring to move into and out of the handle, and a hook configured to be inserted into or separated out of the fixing groove when the button is moved in the handle. 
     
     
       20. The cap assembly of  claim 19 , wherein an end portion of the button which is in contact with the hook is inclined inwardly and outwardly, and the hook has a first end portion being in contact with the button and a second end portion bent to be inserted into the fixing groove. 
     
     
       21. The cap assembly of  claim 8 , wherein a guide pin configured to circumferentially rotate is internally disposed within the mounting hole of the upper cap,
 a guide hole in which the guide pin is inserted is formed on an external side of the second cap device, and 
 the guide hole extends such that the guide pin is locked therein when the second cap device is inserted into the mounting hole of the first cap device, and the guide pin is separated when the second cap device is configured to be moved in an insertion direction thereof. 
 
     
     
       22. The cap assembly of  claim 21 , wherein the guide hole has a start point on a vertical line extending from a pivot point of the guide pin, a first bending point extending upward at an angle at a first side of the vertical line and then bending downward to a second side of the vertical line, a second bending point bending upward at the second side of the vertical line, and a third bending point bending downward thereof, having a heart shape. 
     
     
       23. The cap assembly of  claim 22 , wherein within the guide hole, a distance from the start point to the first bending point is a longest and a distance from the second bending point to the third bending point is a shortest. 
     
     
       24. The cap assembly of  claim 22 , wherein within the guide hole, only the first bending point is disposed at the first side of the vertical line, and the second bending point and the third bending point are disposed at the second side of the vertical line. 
     
     
       25. The cap assembly of  claim 21 , wherein a return plate elastically supported by a return spring is disposed in the mounting hole of the upper cap, so an elastic force that pushes the second cap device out of the mounting hole is applied to the second cap device. 
     
     
       26. The cap assembly of  claim 8 , wherein the first cap device is disposed such that the upper cap has a greater distance from the inlet of the fuel injection passage than the lower cap, and has bridges connecting the lower cap and the upper cap to each other.